Every February Yosemite waterfall turns to lava

YOSEMITE NATIONAL PARK, Calif. (AP) -- Nature photographers are flocking to Yosemite National Park hoping to catch a glimpse of a rare phenomenon that happens only in mid-February.

That's when the setting sun hits an ephemeral waterfall on El Capitan at just the right angle, making it appear as if lava is flowing over the top. It lasts for only about two minutes while the earth and sun are optimally aligned.

The spectacle that transforms Horsetail fall is reminiscent of the old firefall of embers that occurred nightly off Glacier Point until 1968. But this natural fire fall had gone largely unnoticed until 1973.

Now Internet chats have spread the word and hundreds of photographers hoping for clear skies will converge until February 24, when the sun's angle changes and it disappears for another year.